Two Plus Two, Still

Earlier I recorded my take on the 2+2=5 controversy swirling around James Lindsay on Twitter. But aside from people who may be engaged in creative wordplay to remake math curricula in the Critical Social Justice image, some of their goofy suggestions provide legitimately interesting conversation so I recorded a video about it on another channel separated from the funky anti-objectivist social justice nonsense.

The topics worth talking about in more detail are summarized below. Needless to say, all of these depend on a prior understanding that two plus two does equal four and then asking new, interesting and different questions.


In the coffee cup example, I highlight the difference you get between using words rigorously vs. not. Playing with the definitions in words in tricky words makes for fun puzzles and games, but it destroys any chance you have at rational inquiry.

Counting Complicated Things

What happens when instead of something like rocks, you have something like rabbits where if you leave and come back later, you can’t expect the number to stay the same?

Change of Base

What would the world be like if, instead of using the digits 0 through 9 to build numbers (in base 10), we had more or fewer number symbols at our disposal?

Clock/ Modular Arithmetic

What would the world be like if numbers wrapped around like on a clock? Once you counted up high enough, you had to loop back around to zero?

Precision and Rounding Errors

How handling of numbers gets more complicated when you to take measurement error and rounding error into account.

For those curious, that’s a separate channel that a friend encouraged me to make during the immense downtime provided by COVID-19. I worked for twelve years doing private tutoring, primarily in high school math and he talked me into doing a bit of a brain dump and sharing some of the concepts that I kept repeating to my students over and over again.

Of course it’s the summer right now, and the coming school year is up in the air. But if you know of anyone who wants help with math, I did a couple of sessions on Zoom with my iPad before school ended in June and they went very well. More information is available at

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